Some digital radiography imaging systems have an X-ray source and an X-ray imaging detector that are coupled together and supported in a manner that provides for a plurality of degrees of freedom of movement so that the imaging system can be properly positioned relative to a subject. Often, an operator control interface having a display screen is integrated into the system. A problem occurs when an operator needs to access the control interface and it has been shifted out of a convenient position for maintaining control of the apparatus by the movement of the imaging system.
There are prior systems that are adapted to maintain a correct viewing orientation of the image on the operator control interface with respect to the operator by adjusting the image on the display screen to compensate for the tilting movement of the X-ray source and an X-ray imaging detector. That is, the image to be displayed is modified in accordance with the tilting movement. The image data stored in memory is remapped from memory locations to positions on the display screen in order to display the image on the screen in a desired orientation. Such systems require re-computation, resizing, and redrawing of the image on the display screen in conjunction with the movement of the patient table. The readability and legibility of the display suffer due to angularities of the screen text in relationship to the operator. See, for example, U.S. Pat. No. 4,674,107 wherein orientation of an image on a display is maintained constant with respect to a main support during pivotal motion of the X-ray system by rotating the displayed image as a function of the direction and extent of the pivotal motion. PCT Application WO 2004/064039 discloses an imaging device with means for rendering the detector orientation and the display orientation essentially equal, but does not disclose maintaining a particular orientation of the display relative to an observer.
Other digital radiography imaging systems will “flip” and redraw the image on the display screen after the display and X-ray source have been subject to a given amount of angular rotation (e.g., a 45 degree angle in either direction) by an operator in positioning the source.
In other digital radiography imaging systems such as shown in U.S. Pat. No. 3,702,035, the display screen is mounted on an independent support arm that does not move in conjunction with the movement of X-ray source. Rather, it maintains a fixed position. Such systems have limited ability to handle different orientations of individuals for imaging, and must include additional support structure for the display monitor. Furthermore, such systems occupy significant floor space, which is disadvantageous in emergency room situations.
There exists a need for a digital radiography system that has a display and controls that are always in the same orientation for an operator. Additionally, there exists a need for ergonomic features for controlling the operation of an imaging system with an X-ray source and detector in a variety of positions.